With its web weaponry ability, a Leng spider has created a delicate counterbalance of bladed pendulum webs that swing through the lowest 10 feet of this chamber. The Leng spider can release the webs with a simple tug of one of its signal lines, setting off the trap as a free action. The spider is not immune to the trap, however, so it attempts to stay in the upper reaches of the chamber until the pendulums lose momentum after 1d4 rounds.